Observational challenges in Ly-alpha intensity mapping

Understand

Intensity mapping (IM) is sensitive to the cumulative line emission of galaxies.

• As such it represents a promising technique for statistical studies of galaxies fainter than the limiting magnitude of traditional galaxy surveys.
• The strong hydrogen Ly-alpha line is the primary target for such an experiment, as its intensity is linked to star formation activity and the physical state of the interstellar (ISM) and intergalactic (IGM) medium.
• However, to extract the meaningful information one has to solve the confusion problems caused by interloping lines from foreground galaxies.